My friend just bought a trike with the Motortrike conversion. He is getting use to riding it, which is different than anything we've ridden before. The concern is that the front end has a "shimmy" in it. The Honda dealer said that it has a lot of stuff wrong with the front and rear. Another bike repair place says that the rear wasn't bad, it may just needed some adjustments. The big concern is the wobble in the front. At highway speed, it's fine; at low speeds when we take our hands off the handle bars is when we notice it (and it is noticeable). When we called the seller back he did admit he changed the handle bars because he couldn't reach them. Could something else have been done?

To be honest , I would jack up the front and check steering bearing play, front tire for pitting or out of round. Maybe even wheel bearings just for starts. I don't think a set of handle bars are the culprit. Who is this Honda dealer so I don't go there ....Just sayin'. Good luck LesH

toanogreen wrote:My friend just bought a trike with the Motortrike conversion. He is getting use to riding it, which is different than anything we've ridden before. The concern is that the front end has a "shimmy" in it. .... etc .... The big concern is the wobble in the front. At highway speed, it's fine; .... at low speeds when we take our hands off the handle bars is when we notice it (and it is noticeable).

Keep thy hands on the handle bars.

What you are describing is entirely normal.

That is no longer a motorcycle, it is a TRIKE now. If it has not been raked with a fork rake modification, it still has the longer trail of a BIKE. Bikes and Trikes steer differently, that's just how it works. I've owned my trike 12 years as a choice, I've done the rake kit myself. I still ride and enjoy a two wheeled GL as well. They are different in so many ways. Below is a quote of something I wrote addressing this a fair number of years ago.

A buggy in front of Walmart has "casters" on the front, the wheel will turn. You'll notice that the wheel touches pavement behind the pivot of steering axis (an imaginary line drawn through the steering stem or pivot that continues to road or other surface). These casters have a lot of trail, which is why they will readily follow where the buggy wants to go. You don't steer the buggy by turning the casters, you steer it by applying pressure on the handle at back and as you know, they like to go down hill, not across hills or grade.

Wonder why a buggy rolling across a parking lot turns and goes the shortest way down hill to a car door? Wonder why most all stores slope parking lots away from the store? Rain and buggies.

A motorcycle has this trail built in too, it works better for steering a bike with handle bars attached to the caster because a bike leans when it steers. Even then, trail, or more of it, slows steering response too, but it makes a bike easy to handle, if left as a bike.

When converted to a trike, now we are back like the buggy, we don't lean. We are however attempting to steer it with handlebars connected to the casters. As a caster, it likes to follow, not lead. Trikes do not lean, one does not countersteer to steer it. Lots of trail means a trike will want to always fall off to the crown of the roadway, it means that while you steer left in that left hand sweeper, centrepidal force tries to steer that same front caster straight off the road.

Grandpa's tractor was a "G" model John Deere, it had tricycle style wheel placement. It was much like our trikes with one exception, it had "0" (zero) trail. You look at it and the steering stem axis hits the road exactly where the front wheel does. No lead, no trail. It would go in a circle all day if you take your hands off the wheel after turning it, likewise, it was very easy for this fellow as an 8 year old to steer on the roughest farm road or across grandpa's corn or tobacco field with plows.

Stock, our Gold Wings have near 4.5 to 5 inches trail, the wheel touches the road that far behind the steering stem axis. The front fork tubes and steering stem are right about 30 degrees from verticle.

A rake kit adds 4.5 or 6 degrees to that through offset machining of the triple trees, so that instead of the steering stem and tubes being parallel, the tubes are 4.5 or 6 degrees skewed forwards. This additional rake swings the tubes forwards toward the front, towards the steering stem axis, and it reduces trail to nearer 2 - 2.5 inches, still leaving some trail.

This swinging of the tubes in an arc also will lower the front of the trike as they are swinging through an arc from 30 degrees to more like 34.5 or 36 degrees from verticle. This is why Champion includes fork extensions (they did with my 6 degree kit in 2004), why CSC includes longer tubes, and why Bud Redmon had custom extensions machined for his 1200 trike.

You do not want "0" trail, you want the front to want to straighten up somewhat, you just want to lessen effort required to point it the way you want it to go.

You do not want it to go past "0" trail and into a lead condition, as then the front wheel will want to either fall off to left or right side full lock .... just like your trike does now if you let it roll backwards with any speed. Very dangerous at 50+ mph.

Many trike dealers will try and tell customers that their trike does not need a rake kit like others, and truth is they all can be ridden with stock front ends. By selling theirs as a kit not needing a rake, they are selling you on the idea that all others do, thus placing their product at a $1,000 plus advantage.

You cannot "build" the benifits of a rake kit into a kit bolted on the back of a motorcycle frame converting it into a trike unless you drastically raise the rear of the trike to reduce trail.

Truth is that all trike kits for the Gold Wing will derive the same benifit from a rake kit, a lighter steering effort and greater control of where the trike goes under road conditions, acceleration and cornering.

Later ......

Now, that "shimmy" as you call it is just the front wheel which is still a "caster" of sorts (whether it's raked or not just changes it's trail, but trail remains). Imagine that Walmart cart as you push it and one of the rear wheels hits a ink pen laying on the floor, the front of the cart is pulled in that direction and the front casters follow. On the trike when a rear wheel meets any resistance, a bump, hole, rock, the front wheel is still pulled to that side and if your hands are not on the handle bars, it does so unrestrained until that rear wheel passes it's obstruction, and it will come back to straight or react to the next impediment to be encountered by a rear wheel. At higher speeds, the gyroscopic effects of the tires / wheels and the trike's mass all dampen it mostly .... though you'll still feel the pull as the trike tries to fall off the roadway crown. But at low speed, with no hands on handle bars .... it's gonna react left and right in a shimmy like motion.

Keep hands on the handle bars. Keeping just one hand on will go along ways to dampen it .... keeping both on at low speed is even better .... though you'll still feel the bumps, etc pull some left & right at low speeds.

My '97 GL1500 has been a Lehman trike since 1998 and I put a 6 degree Champion EZSteer on it in October 2004, it is meticulously maintained, nothing is loose. It has always behaved as you describe if I am at low speed and remove one or both hands from the handle bars ..... not as bad as before the rake kit .... but it still will do it at low speed. That is just in the nature of the TRIKE.

moldor wrote:Very informative - I've never seen the steering geometry explained is such a clear manner.

Would you can to expand on that explanation to include the benefits or problems with Leading Link front suspension ?

Thank You for the kind remarks.

As to link type forks and my "ramblings" ..... I know they have been used on motorcycles a long time. BMW used them on all of their MC for years thoughthey were of Earles design. Instead of sliding fork legs on tubes they use a fixed fork leg with a "link" between the pivot at lower end of fork and the wheel axle. When encountering bumps, etc .... the link swings the axle through an arc which itself causes some change to trail (you always want trail in forks on MCs and trikes, just different amounts .... more on MC, less on a trike or sidecar app).

Link type forks are easily manipulated to change trail with mods but they do always swing the axle through that arc whether they use a simple swing arm like wheel mount or a parallel linked setup. They can be built very robustly, but costs go up if you are a MC manufacturer selling large numbers of bikes. Some are made to be adjustable simply, others require mods. Some are cheaply made of stamped steel. Their spring / shocks are easily accessed without disassembly.

I don't have link type forks .... those are just some of their good points as I see them. On the flip side, all pivots are exposed to weather and are points for maintenance. There's a lot to clean there, not like a simple set of fork sliders and tubes.

But those are just my ramblings .... here's a link that likely tells you more than I ever could, for though I've ridden a buddies '60s BMW, I've never owned anything with them. http://bmwdean.com/earles-fork.htm

toanogreen wrote:Thanks CrystalPistol. That is extremely clear and rational.

Well, I hope it helped. We aren't but a couple hours apart .... but I know there are some trike folks there at VA-O .... there are two other chapters just east of you as well. Trikes are a different ride than bikes, I know. Once that is accepted, once we stop expecting it to be a bike, we find it has it's own charm. Fast braking, great towing for a trailer, easy to pull off in the grass for a photo op with that Nikon, no serious danger of sliding the front out from under you on that wide white stop bar after a rain storm, long rear tire wear .... but fronts generally every10-15K miles.

There is even a fairly new "TRIKE" only front tire offered by Avon now that is intended for Trikes based on GL1500 & GL1800 platforms. It's the Avon Cobra TRIKE Front 130/70R18 (a radial) product number 90000020646. It will say "TRIKE" on the sidewall in big letters. It has a different construction, tread profile. Do yourself a favor, look it up, read some reviews. It will tame some of that shimmy as well and it smooths out those roadway bumps.